Development of NEG Coating for RHIC Experimental Beamtubes
Development of NEG Coating for RHIC Experimental Beamtubes
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DOI：
10.1109/pac.2005.1591384
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发表时间：
2005-05
期刊：
影响因子：
--
通讯作者：
D. Weiss;P. He;H. Hseuh;R. Todd
中科院分区：
文献类型：
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作者：
D. Weiss;P. He;H. Hseuh;R. Todd
随着RHIC束流强度的增加超出了原来的范围，在一些区域观察到了压力上升。发光极限压力的升高与电子多次碰撞、电子激发脱附和束致脱附有关。非蒸散型吸气剂(NEG)涂层束管已被证明能有效地抑制同步辐射装置中的压升。标准波束管已由供应商提供NEG涂层，并添加到许多RHIC超高电压区域。BNL正在开发一种圆柱形磁控溅射系统，用于对安装在RHIC实验区的特殊铍光束管进行NEG涂层。它的特点是一个中空的液冷阴极，在7.5 cm外径光束管上产生的功率密度为500W/m，沉积速度为5000埃/小时。阴极是一根部分覆盖着锆带和钒带的钛管，用于水平涂覆4m长的腔室。条带和磁体被布置成提供均匀的溅射分布和沉积的NEG组合物。对NEG涂层管的真空性能进行了测试。用能谱、俄歇电子能谱和扫描电子显微镜对涂层进行了分析。给出了系统的设计、开发和分析结果。
As RHIC beam intensity increases beyond original scope, pressure rises have been observed in some regions. The luminosity limiting pressure rises are associated with electron multi-pacting, electron stimulated desorption and beam induced desorption. Non-Evaporable Getter (NEG) coated beamtubes have been proven effective to suppress pressure rise in synchrotron radiation facilities. Standard beamtubes have been NEG coated by a vendor and added to many RHIC UHV regions. BNL is developing a cylindrical magnetron sputtering system to NEG coat special beryllium beamtubes installed in RHIC experimental regions. It features a hollow, liquid cooled cathode producing power density of 500W/m and deposition rate of 5000 Angstrom/hr on 7.5cm OD beamtube. The cathode, a titanium tube partially covered with zirconium and vanadium ribbons, is oriented for horizontal coating of 4m long chambers. Ribbons and magnets are arranged to provide uniform sputtering distribution and deposited NEG composition. Vacuum performance of NEG coated tubes was measured. Coating was analyzed with energy dispersion spectroscopy, auger electron spectroscopy and scanning electron microscopy. System design, development, and analysis results are presented.